History and Physical Examination

Involuntary facial movement is the only symptom of hemifacial spasm. Fatigue, anxiety, or reading may precipitate the movements. Spontaneous hemifacial spasm manifests with facial spasms that represent myoclonic jerks and are analogous to segmental myoclonus, which may affect other body regions. Postparalytic hemifacial spasm, following facial nerve trauma such as Bell palsy, manifests as facial synkinesis and contracture.